A full independent investigation has started after a man suffered a cardiac arrest after he was shot with a police Taser gun in Liverpool.

The stun gun was fired at the 22-year-old after a disturbance on the Albert Dock in the early hours of Sunday.

The Merseyside force was due to manage its own inquiry into the incident.

But the Independent Police Complaints Commission (IPCC) said an independent inquiry would be in the public interest.

The IPCC has seized the Tasers carried by the two officers involved for examination.

The officers had been called out to a disturbance involving five men at the Premier Inn on Albert Dock at about 02.50 BST on Sunday when the Taser was used.

Four men arrested

The man, from West Derby, remains in Liverpool Royal Hospital in a stable condition.

Merseyside Police referred the incident to the IPCC and an investigator decided, following initial inquiries, to manage an investigation by the force's own professional standards department.

However, the IPCC then viewed CCTV footage and made the decision to take over the investigation.

IPCC commissioner Naseem Malik said: "A young man has ended up in hospital following an incident in which a Taser has been discharged and we have decided it is in the public interest for this investigation to be fully independent.

"Our investigation will examine all the circumstances of the incident and, in particular, the use of Taser."

Four men - three aged 22, 27 and 32 from north Liverpool and one aged 23 from Maryport in Cumbria - were arrested on suspicion of affray.

The 27-year-old was also arrested on suspicion of assault and possession of a controlled drug and the 22-year-old also on suspicion of possession of a controlled drug.